<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<style>
			*{
				margin: 0;
				padding: 0;
			}
			.pa{
				width: 100%;
				height: 800px;
				background-color: deeppink;
				display: flex;
				flex-direction: column;
				justify-content: center;
			}
			.ch{
				width: 500px;
				height: 100px;
				line-height: 100px;
				background-color: #008000;
			}
		</style>
	</head>
	<body>
		<div class="pa">
			<div class="ch">但是看看看看打开看课件快快快开开口率是的看看</div>
		</div>
	</body>
</html>
